RETRACTED: The structure of SV40 large T hexameric helicase in complex with AT-rich origin DNA

RETRACTED: The structure of SV40 large T hexameric helicase in complex with AT-rich origin DNA

Blog Article

DNA replication is a fundamental Tote Bag biological process.The initial step in eukaryotic DNA replication is the assembly of the pre-initiation complex, including the formation of two head-to-head hexameric helicases around the replication origin.How these hexameric helicases interact with their origin dsDNA remains unknown.

Here, we report the co-crystal structure of the SV40 Large-T Antigen (LT) hexameric helicase bound to its origin dsDNA.The structure shows that the six subunits form a near-planar ring that interacts with the origin, so that each subunit makes unique contacts with the DNA.The origin dsDNA inside the narrower AAA+ domain channel shows partial melting due to the compression of the two phosphate backbones, forcing Watson-Crick base-pairs within the duplex to flip outward.

This structure provides the first snapshot of a hexameric helicase binding to origin dsDNA, and Wedge Cushions suggests a possible mechanism of origin melting by LT during SV40 replication in eukaryotic cells.